וְלָקַ֣ח מְלֹֽא־הַ֠מַּחְתָּה גַּֽחֲלֵי־אֵ֞שׁ מֵעַ֤ל הַמִּזְבֵּ֙חַ֙ מִלִּפְנֵ֣י יְהוָ֔ה וּמְלֹ֣א חָפְנָ֔יו קְטֹ֥רֶת סַמִּ֖ים דַּקָּ֑ה וְהֵבִ֖יא מִבֵּ֥ית לַפָּרֹֽכֶת׃
Il remplira l’encensoir de charbons ardents, pris sur l’autel qui est devant le Seigneur; prendra deux pleines poignées d’aromates pilés menu, et introduira le tout dans l’enceinte du voile.
Rabbeinu Bahya
ויתנו בהן אש וישימו עליה קטורת, “they put fire in them (the censers) and placed incense in them.” According to the plain meaning of the text Nadav and Avihu’s sin consisted in that they introduced alien, i.e. man-made, fire into the sacred precincts. The regulations pertaining to the incense offering required that the fire be taken from the Altar and that the incense be burned up by that fire. The Torah had spelled this out in Leviticus 16,12: ”he shall take a shovelful of fiery coals from atop the Altar that is before Hashem.” Nadav and Avihu thought that the actual fire from the Altar was required to totally consume the animal sacrifices. This was a sin as they demonstrated a lack of faith, not trusting G’d to make heavenly fire descend on the sacrifices and able to consume the sacrifices; this is why they brought additional fire to consume the incense. By bringing their own fire they made the miracle of heavenly fire descending seem less relevant, thereby causing a desecration of the name of the Lord in the eyes of all those who had observed what they did. This is why their punishment fitted their sin, as that same heavenly fire they did not trust to materialise consumed their own insides. This is the explanation of Raavad of what happened .
Kli Yakar
Therefore, the obligation of explanation falls upon me to advocate for all these opinions, and to say that all of them found support from this verse because they found it difficult [to understand]: Isn’t it already stated And the sons of Aaron the priest shall put fire, etc. (Leviticus 1:7) that there is a commandment to bring [fire] from ordinary [sources], so how can it say which He had not commanded them? And one cannot say, as Abarbanel says, that they should have taken the fire for the incense from the altar of burnt offering, because that commandment was [given] after the death of Aaron’s sons, and there it states And he shall take a censer full of burning coals of fire from before the Lord, etc. (Leviticus 16:12). Therefore, it is appropriate to interpret this strange fire as referring to strangeness and alluding to other matters that are hinted at in the [phrase] strange fire.
English Explanation of Mishnah Yoma
They brought out to him the ladle and the pan and he took two hands full [of incense] and put it into the ladle, a large [high priest] according to his size, a small one according to his size and thus was its measure. After putting the coal-pan down on the fourth terrace they would give him a ladle in which to bring the incense into the Holy of Holies and a pan in which there was a preparation of incense, made in the house of Avtinas (see 1:5; 3:11). He would take two handfuls of the incense from the pan and put it into the ladle. It didn’t matter whether he was large and would therefore take large handfuls or small and therefore would take small handfuls. The measure of two handfuls was set by Leviticus 16:12.